Process of preparing peat.



UNITED STATES PATENT OFFICE.

CHARLES ULMER GREELEY, OF BANGOR, MAINE.

PROCESS OF PREPARING PEAT.

Specification of Letters Patent.

" Patented Aug. 13, 1907.

Application filed August 26, 1905, Serial No. 275,970. Renewed May 7, 1907.- Serial-No. @2344.

'To all whom it may concern:

Be it known that 1, CHARLES ULMER GREELEY, a

citizen of the United States, residing at Bangor, in the crude or natural peat and similar non-fibrous vegetable deposits, so that the same maybe freed from moisture by pressure and subsequently used for manufacture into compressed fuel briquets, and for other uses to which it is well adapted, such for instance as an insulator for electrical conductors, and'as a substitute I for wood and other materials for interior decorative work.

I Peat in its natural state has a well known peculiarity, which, up to the present time, has been the one really insuperable bar to its satisfactory manipulation, and to its successful employment as a fuel and for other purposes, on a commercial scale. There are two phases of this peculiarity. First, unless a very large proportion of the contained moisture, including much of that incorporated in its cellular structure, be first removed by some means, it cannot be subjected to lasting pres-' sure, the elasticity of the combined mass being such as to resist all efforts in that direction by whatever method. Second, after so much as is practicable of the moisture has been removed by drainage, the relatively large amoiint still remaining is so intimately admixed with the particles of the peat, and is so lockedup in its cellular structure, that 1 no method of applying power has been discovered, adequately capable of re-' I moving this water to such a degrca as would fit the peat for compression into briquets or bodies of any shape. Under pressure, the particles of peat, instead of separating from the water, clung tenaciously to it, approximating a chemical solution in its manifestation of afiinity. V In many processes heretofore employed, heat has been used todrive off the moisture, but whenso. treated the peat will dryin a crumbly condition, dry heat having a' destructive effect upon the peculiar properties of the cohesive or binding material, which is one of its constituents. This crumbly condition,

so resulting, is not materially improved by compression.

The minute particlcslose that cohesive tendency which is native to therein the natural state; and the loss, once a(-complished,2cannot be remedied so as to produce a compact and durable body under compression, save ,by the introduction of some foreign binding material. A binding material for such purpose admitted.

which would be cheap, unobjectionable during combustion and capable of retaining the peat in compact shape when heated, has not yet been placed on the market. l i I It is found thatfowing to its naturally elastic structure and character, the rapid drying of peat under any conditions, other than those of compression (to a degre'e'suflicient to remove the airand leave the interstices occupied by water alone and in only small percentage) by permitting the access 'of air to the surfaces of the minute particles throughout'its structure, re-

sults inevitably in the drying of the binding constituent at all such surfaces long before the moistureis removed from the interior ofsuch particles; and i treated as to render it susceptible to mechanical pres-' sure, so as to remove therefrom the moisture to any'de-' gree desired for the manufacture of peat fuel, and an extensive variety of other articles to which it is Well adapted. Toaccomplish this, the peat is so treated as to break up the cellular structure and at the same time destroy or negative the strong afiinity or attraction existing between the water and the'peat.

- The crude peat, if in such large solid pieces as usually come from a well drained bog, or if it contains any considerable proportion of moss that is only partially con- I verted to the true peat form, is passed between suitable rollers to reduce the whole to a soft and homogeneous mass. The object of this is not to cru'shthe cellular structure (which in the present process is an unnecessary step), but simply to render the material capable of being expeditiously treated as hereinafter described, by admitting the solutions referred to into intimate contact with all its particles without loss of time. If the raw material be in a semi-fluid state, without hard lumps, it is introduced into the treating vat without passing betweenthe rolls. r

-In suitable condition, as above explained, the peat is placed in the treating-vat, which may be formed of any '-m ate weight and bulk of the charge being known, an amount of water, equaling from one to two times that bulk, according to the relative solidity of the peat, is

It is unnecessary to be exact in the proportion of water, as a considerable excess is found to do no harm. Next is added a chemical agent in aqueous solution, Whose action, on raising the mixture to the boiling point, is to break up the structure of the peat, swell or expand its mass, and extract into solution the gluelike constituent essential to the cohesion of the particles. The mixture is kept as nearly as may be at the boiling point for a period varying from ten to twenty minutes, dependent upon the quality of the peat, with constant agitation. It is immaterial in what order the peat, water and chemical solution are admitted, so far as concerns the effect produced, so long as the mixture is kept at the required temperature for the period neces sary to expand the peat thoroughly and break up its structure as much as possible.

Itis found that a considerable number of chemical agents, particularly those of alkaline reaction, will accomplish in varying degree, the specific results desired in this stage of the process, namely, a sufficient breaking-up of the structure of the peat; the expanding of its mass; the extracting into solution or partial solution of the binding constituent, and the changing ofthe entire mixture into a condition fit to be acted upon atthe next stage of the process. The substances tested for this purpose, vary in the extentof the time required for their action, and in the relative amount necessary to accomplish the desired results. All things considered,

including its abundance and cheap'ness, it is found that similar alkaline substances may be employed without departing from the invention.

One of the important features in this stage of the i process is the dissolving out of the binding constituent of the peat in as large a proportion as is practicable, so that later it may be deposited in greater proportion on the exterior of the particles instead of remaining locked up within their cellular structure. The amount of the alkaline solution to be used is based ,upon a liberal estimate of the percentage of such binding constituent, and it is found in practice that a proportion of five (5) pounds of sodium carbonate in crystal form to the ton of peat is adequate to accomplish all that is desired in this stage of the process. The action of the sodium carbonate, aided by the heat, is marked by the immediate thickening of the mass; the expansion of the tissues of the peat permitting access of the hot solution to the binding constituent throughout the mass, so that within a very brief period nearly all of it is in solution. It is found that this degree and period of heating the binding constituent in the'continued wet state as described, does not injure its binding quality in the least.

The second stage ofthe process consists simply in the cessation of the heating, the cooling of the mixture by the slow addition, with agitation, of cold water in ,amount about equal to the amount first added, and can rying in solution a chemical agent of acid reaction, which shall not only neutralize the sodium carbonate and precipitate all that it holds in solution, but shall also so affect the ligneous matter held in suspension as to destroy itsai'linity for the moisture of the mixture, and produce in said ligneous matter the tendency to separate from the moisture and become compacted apart therefrom, or, in other words, to coagulate the mass apart from the moisture therein. There are, obviously, numerous reagents which exhibit in varying degree the action here desired. For similar reasons to I those which determined the choice of sodium carbonate for use in the first state of the process, it is preferred to employ common alum (aluminium and potassium sulfate) to complete the process. v

The object of the addition of the cold water, or the production of a change of temperature, is to facilitate the reactions taking place, which are produced much more rapidly in consequence of a change of temperature than if alum or other acidulous solution were added at the same temperature.

A slightly greater bulk of alum than that of the so dium carbonate used, or five and one half (5.5) pounds to the ton of peat, not only neutralizes the sodium and precipitates the dissolved material, but affects the entire mass of the peat after its well known; astringent or 80.

coagulating quality, with the positive and immediate result that the water. will drain away clean and clear from the mass, at once if it is given the opportunity to do so, and the-moisture in the pasty residuum may be readily and perfectly expressed therefrom in a suitable press, to the needful degree of dryness. The peat so treated, comes from the press in perfect condition for being compressed intp any desired form, and for any suitable purpose. Its condition is, in fact, much better than if it were at the same stage of dryness inthe natural state, because none of its elements is in any degree in solution in the remaining moisture and, consequently, it may be powerfully compressed and so formed, for ex ample, into briquets, which, immediately upon their formation and without waiting for or depending upon further drying, are so compact and strong that they may be tossed about violently without breaking. This quality removes the necessity of manual labor in the disposition of the product as it comes from the machine which forms it, and makes it entirely feasible to employ automatic conveyers to transport the product from the machine to the place of storage, with no loss whatever from breakage or crumbling. Furthermore, the briquets or other forms compressed from peat treated by this process, dry out with extreme rapidity; when dry are very hard and compact, and in the ability to withstand handling and transportation are not excelled evenby anthracite coal.

Upon the completion of the treatment described, the. peat is drained in any manner suited to the purpose to which it is to be applied. In the production of fuel briquets, it is found most feasible to discharge the contents of the vat upon a suitably large surface of textile material like burlap of fairly close weave. The water drains away rapidly and of a surprising clearness, 1 15 leaving the peat in the form of a thick paste ready for the press or for an intermediate storage bin.

It will be evident that the entire treatment comprised in the present process requires but a brief period for its completion. The amount treated at a time is limited only by the size of the vat and the means provided for heating and keeping the contents in agitation. With suitable arrangement of vat, and its accessories, including means for admitting the solutions from their respective tanks, and the gaging of all amounts, by

essary torrecite some-of the advantages of the process over any existing means of manipulating peat without its aid. I

Among these are :First, that without materially changing the chemical composition of the peat-product or adding thereto anything to injure its 'burningqfialities or reduce its final fuel value, or detrimental to its use .for any of the varied purposes to which it is suited, the process. with great rapidity and with extremely small expense for large quantities treated, so changes the relation of thepeat and the admixed water that, whereas in the natural state they have so strong an afiinity as to practically be inseparable by mechanical means, in the state in which this-process leaves'them, such affinity is neutralized and destroyed, so that they tend of themselves to separate, and the peat gives up ts moisture freely under pressure, and without loss of 7 any of its constituents. Second, that by this process the need or advantage of preliminary storing of' the peat for a protra'cted period for the purpose of partial drying, is eliminated; thereby saving the time and expense of conveying incident to such storage, as well as the cost of Conveying apparatus for such purpose, and the use of the premises required therefor. Third,- that the process, besides rendering the peat capable of being mechanically dried rapidly and in large quantities, adapts the peat, when applied to the manufacture of fuel, to be compressed into briqucts much superior to those produced without the aid of said process, in that they are hard and compact at the moment of coming from the machine which forms them, and may at once be dropped from a considerable height, shoveled, dumped or otherwise roughly handled without injury from breakage or crumbling. Instead of requiring 'to be conveyed by barrow or. similarly to the drying ground, and there tiered up and turned by hand, as is essential with briquets made from natural peat without pressure, (the latter being of similar delicacy to that of bricks fresh from the brickmaking machine and requiring similar expensive handling,) -the briquets produced with the .aid of my process require no such tender usage, but perfectly withstand transportation and dumping upon the drying area byautomatic eonveyers. Fourth, that this process for the first time makes-possible the manufacture of a perfect article of peat fuel for all purposes, and on a commercial scale, by a system extremely rapid and cheap in operation, employing automatic conveying throughout, and thereby reducing the amount of hand labor to a minimum, and avoiding all occasion for wait or storage from the peat-bog to the drying area. Fifth, that the fuel-product obtained with the aid of this process is of a quality such as cannot be produced by any machine or process without the aid of the process herein described. That is to say, theproduct of my process, compressed into fuel-briquets, fulfils perfectly all of the conditions essential to a peat fuel that shall be really satisfactory in the commercial sense.

While the process 'hereinbefore described has dealt chiefly with the treatment of the material for the production of fuel -briquets, it has many other advantages. It has been found, for instance, that compressedpeat may be employed to advantage as an insulating material. for electrical appliances and conductors, the only essential being a sufficiently close compression and the practical elimination of'air cells. This cannot be sucwoods.

cessfully accomplished, at least, on a commercial scale, by any process now in use, 'but by treating the peat in the manner described, and breaking up its cellular structure and affinity for moisture, a cheapand eflicient insulating material may be manufactured.

. Further, and in similar line, this process makes it possible to utilize peat for a variety of purposes in connection with interior finishing, furnishing and decoration of buildings,an utilization which would remain impossible without the means of expelling moisture sufficiently for compression, while conserving all the other qualities of the peat. By finely comminuting the substance, either before or after treating by this process, the cake or cast of any shape resulting from powerful compression, has, when dry, an extremely close even texture, is finely suited for working inany manner, susceptible of a high and permanent polish, and equal in' hardness and durability to the most expensive of-foreign By simply adding the coloring matter at the first stage of the process, the material may be readily colored throughout its texture, without additional ex- 'pense, save for the coloring matter itself.

It is cvidept that these facts render possible the production, with the aid of this process, of an inexpensive new material, the sources whereof are almost inexhaustible, having many advantages as a substitute for wood, in inlaid flooring, paneling, black piano keys, molding and a variety of similar purposes, where cheapness, ease of working and quality of surface and finish are of importance, rather than tensile strength.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. The process of treating peat and similar non-fibrous vegetable deposits, so that the same may be freed from moisture by pressure and. subsequently used, consisting in-breaking up the cellular structureof the peat, and liberating the water therein, and adding thereto coagulating material. I

2.- The process of treating peat and similar non-fibrous vegetable deposits, so that the same may be freed from moisture by pressure and subsequently used, which consists in heating the mass in the presence of a. material which breaks up the peat and extracts into solution the quasi-albuminous or binding constituents thereof, and then adding thereto coagulating material.

3. "1hat process of treating peat and similar non fibrous vegetable deposits, so that the same may be freed from moisture by pressure and subsequently used. which consists in subjecting the same to the action of an alkaline solution, and then adding theret'o coagulating material.

4. The process herein described for preparing peat and similar non-fibrous vegetable deposits so that the same may be freed from' moisture by pressure, which consists in heating the same in contact with an alkaline solution, and then adding to the mixture an acidulous solution at a lower temperature whereby the mass both in suspension and solution, is coagulated.

5. The process herein described for the preparation of peat and similar non-fibrous vegetable deposits so that the same may be freed from moisture by pressure, which consists of heating a mixture of peat with an aqueous solution having an alkaline reaction, ,and adding thereto slowly, a cold aqueous solution having an acidulous reaction whereby the mass both in suspension and solution, is coagulated'.

6. The process herein described, for the preparation of peat and similar non-fibrous vegetable deposits so that the. same may be freed from moisture by pressure, which consists in expanding and breaking up the structure of the peat by treating the same with an alkaline solution at the boiling point and cooling the same by the addition of an acidulous solution at a lower temperaturewhereby the mass both in suspension and solution, is coagulated.

7. The process herein described for the preparation of peat and similar non-fibrous vegetable deposits so that the same may be freed from moisture by pressure, which consists in dissolving the binding constituent from the interior structure of peat in an alkaline solution by the aid of heat, and precipitating the same by the addition of a cold acidulous solution in excess of the amount necessary to neutralize the alkalinity of said solution whereby the mass both insuspension and solution, is coagulated.

8. The process herein described for the preparation of peat and similar non-fibrous vegetable deposits so that the same may be freed from moisture by pressure, which consists in expanding and breaking up the structure of the peat and extracting therefrom its binding constituent,

by treating the same, at a temperature at or near the boil ing point, with an alkaline solution, and adding to the mixture with constant agitation an acidulous solution at a lower temperature and in amount in excess of that sufiicient to neutralize the alkalinity thereof whereby the I mass both in suspension and solution, is coagulated.

9. The process herein described for the preparation oi peat and'similar' non-fibrous vegetable deposits so 'that' the same may be freed from moisture by pressure, which consists in destroying the atfinity naturally existing be tween the peat and the contained water by breaking up 10. The process herein described, for the preparation of peat and similar non-fibrous vegetable deposits so that the same may be freed from moisture by pressure, which consists in changing the structure and nature of the peat, so that the water contained therein may be rapidly expressed by mechanical means; by breaking up the structure thereof, and dissolving such of its constituents as are readily soluble in an alkaline solution, with the aid of heat and agitation, precipitating the constituents so dissolved by the addition of a cold acidulous solution having an astringent quality, and increasing the tendency of parts in suspension in the first named solution to separate from the water thereof, to contract and to become compacted, by adding an excess of said acidulous solution.

11. The herein described process of treating peat and similar non-fibrous vegetable deposits so that the same may be freed from moisture by pressure, said process con- In,testimony whereof I afiix my signature, in presence of two witnesses.

' CHARLES ULMER GREELEY.

Witnesses: 1

WiLLIaM K. NEAL ZANA F. RICHARDSON. 

